/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package servlets.student;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.URLConnection;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author FRIENDS
 */
@WebServlet(name = "downloadmaterial", urlPatterns = {"/student/classes/downloadmaterial"})
public class downloadmaterial extends HttpServlet {

    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException 
    {
        
        //response.setContentType("text/html;charset=UTF-8");
        //PrintWriter out = response.getWriter();
        String filename=request.getParameter("url");
        response.setHeader("Content-disposition","attachment;filename=\""+filename+"\"");
        //getServletContext().getRealPath("/uploads"),filename)
        //String contentType=filename.substring(filename.lastIndexOf(".")+1);
        //System.out.println("content type   :"+contentType);
        //if(contentType=="")
        //{contentType="application/octet-stream";}
        File file=new File(getServletContext().getRealPath("/uploads"),filename);
        BufferedInputStream bis=new BufferedInputStream(new FileInputStream(file));
        int contentLen=bis.available();
        //response.setContentType(contentType);
        response.setContentLength(contentLen);
        
        ServletOutputStream output=response.getOutputStream();
        byte[] buff=new byte[4*1024];
        int bytesread;
        while((bytesread=bis.read(buff))!=-1)
        {
            output.write(buff,0,bytesread);
        }
        output.flush();
        bis.close();
        output.close();
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /** 
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>
}
